工业纯氯化钙应用于微生物胶结粉土的研究  

Study on the Application of Technical Pure Calcium Chloride in Silt Biocementation

作　　者：尉迟衍春 赵志峰[2] YUCHI Yanchun;ZHAO Zhifeng(Dongying Construction Drawing Review Center,Dongying 257000,China;College of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]东营市建设工程施工图审查中心,山东东营257000 [2]南京林业大学土木工程学院,南京210037

出　　处：《三峡大学学报（自然科学版）》2024年第6期73-79,共7页Journal of China Three Gorges University：Natural Sciences

基　　金：国家自然科学基金项目(51578293)。

摘　　要：利用微生物诱导碳酸钙沉积(MICP)能对土体进行有效加固,但目前胶结液配置多采用分析纯试剂,成本较高.虽然有研究表明采用工业纯试剂也能获得较好的加固效果,但相关研究还不够深入.采用工业纯氯化钙替代胶结液中的分析纯氯化钙,开展了溶液和土体条件下的试验研究.在溶液环境下,通过铵根离子浓度来反映尿素水解情况.结果表明:铵根浓度随着工业纯钙离子浓度的提高而逐渐下降;碳酸钙生成量随着钙离子浓度的提高先增加后降低,过高的钙离子浓度对尿素水解有明显的抑制作用.当胶结液浓度不超过1.25mol/L时,工业纯与分析纯氯化钙的碳酸钙生成量比较接近.对粉土采用两种纯度的氯化钙进行MICP处理,均能对粉土进行有效加固.工业纯和分析纯氯化钙处理试样的强度均随着浓度先增加后降低,采用工业纯氯化钙处理的部分试样强度甚至超过了分析纯.SEM结果表明,采用工业纯氯化钙处理的试样中生成了大量碳酸钙晶体,增加处理轮数,可提高试样碳酸钙生成量和无侧限抗压强度.Soil mass can be reinforced by microbially induced calcite precipitation(MICP)technology,however at present the preparation of cementation solution mostly uses analytical pure reagents which resulting in high costs.Although some studies have shown that using technical pure solution can also achieve good effects,relevant research is not in-depth enough yet.Technical pure calcium chloride is used instead of analytical pure calcium chloride in this research,and experiments under solution and soil conditions are conducted.In solution environment,urea hydrolysis can be reflected by concentration of ammonium ions.The results indicate that the concentration of ammonium ions gradually decreases with the increase of technical pure calcium ion concentration.The calcium carbonate amount first increases and then decreases with the rise of calcium ion concentration,and excessive calcium ion has negative effect on urea hydrolysis.When the concentration of cementation solution below 1.25mol/L,the calcium carbonate amount generated from industrial and analytical pure calcium chloride is relatively close.Two types of purity calcium chloride are used for MICP treatment of silt,and both can effectively reinforce the silt.The strength of samples treated by two types of calcium chloride both increases first and then decreases with concentration of the cement solution,and the strength of some samples treated by technical purity calcium chloride even exceeds that of analytical purity.The SEM results showed that a large amount of calcium carbonate crystals are generated in the samples treated with technical pure calcium chloride.The calcium carbonate amount and unconfined compress strength can be achieved by increasing the treatments of technical pure calcium chloride.

关 键 词：微生物诱导碳酸钙沉积 氯化钙纯度 工业纯 尿素水解 加固强度 

分 类 号：TU472[建筑科学—结构工程]